Q-Man Posted June 6, 2004 Share Posted June 6, 2004 Sorry for that drawing. I ment to post a few pictures of my modified Klipschorn. I thought that drawing was one. The drawing is a crude design for a new room that I'm working on. I'll try to find the pictures later and post a couple. Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted June 6, 2004 Share Posted June 6, 2004 Q_man, I'm glad you goofed! That drawing is very interesting. Al K. Quote Link to comment Share on other sites More sharing options...
Deang Posted June 7, 2004 Share Posted June 7, 2004 "The drawing is a crude design for a new room that I'm working on..." That's a crude drawing? That's what mine look like when I'm getting serious, lol. Shawn -- thanks for the time you took to do that well written explanation. I've read similiar things elsewhere, and even how they relate to some other speakers. If I'm remembering things right, isn't there some debate regarding the audibility of what you're talking about? Maybe some people pick up on it, and other's don't. Interesting stuff. Did PK ever address the issue in writing? Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted June 7, 2004 Share Posted June 7, 2004 Dean, Try downloading the paper I wrote called "A case for extreme slope networks" from my web site. I think it deals with some of the points Shawn made. Al K. Quote Link to comment Share on other sites More sharing options...
sfogg Posted June 7, 2004 Share Posted June 7, 2004 Dean, "isn't there some debate regarding the audibility of what you're talking about?" There is debate regarding absolute phase audibility overall in a speaker (seems to basically be inaudible on music but can be audible on specific test tones) but very little debate about phase at the crossover points since it will alter FR at crossover points. As far as interaction between drivers that is easily audible if you know how to listen for it or what to listen for. BTW, the info I posted I didn't get from Al. I got it from papers and information written by people like Dr. Floyd Toole and Kevin Voecks who have done lots of research (and double blind tests) on things like audibility of phase, off axis response and so on. Shawn Quote Link to comment Share on other sites More sharing options...
John Warren Posted June 7, 2004 Share Posted June 7, 2004 A registration requirement with this BB is that manufacturers reps identify themselves. Given the information posted by Lee here AND his setup is posted concurrently on ALK website, the impression is given that Lee is an ALK rep. He is not. If he was, it would require that a statement be made to that effect. <?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /> My questions were completely justified and clarification was in order. Also, for those of you that post on other BBs and moderated Usenet sites manufacturers are banned from posting entirely. Some of you know that I have pitched the JBL 2404H tweeter as an upgrade. I have a page devoted to it on my website. Many, many of the members on this board have asked me questions about it. If I was receiving compensation of some type from JBL for posting the 2404H upgrade on my website, how would that sit? Especially after you purchased a pair based, without hearing them, on my recommendations. I suspect that a few of you would be pissed-off especially after plunking down $600 for a pair of the tweeters alone. For the record, I am not affiliated with JBL and if I was, I would state it. I have no axe to grind with ALK on this. I consider him a manufacturer and, as such, hold him to a different standard than an individual contributor. Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted June 7, 2004 Share Posted June 7, 2004 John, Your objections are noted. That makes ONE OF US! .................... Oh, BTW: Here's a little quote from somebodies web site: ***Please note that manufacturing rights are the property of The Audio Engineering League. Sounds like an equipment manufacturer to me. Al K. Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted June 7, 2004 Share Posted June 7, 2004 Guys, The subject of phase error audiblilty has been a subject I have been quite interested in investigating. After a lot of experimenting I have convinced myself that the type of phase errors created by time delay between drivers (time alignment errors) and crossover network filters is totally inaudible. Here is an experiment that I did a week or so ago to finalize my thinking on the subject: First a little background.. Consider what a square wave is composed of with respect to its harmonic spectrum. It is a fundamental frequency (a sine wave) combined with all its odd order harmonics (also sine waves) with amplitude equal to 1 / n times the fundamental voltage level. Each harmonic starts at zero time from zero voltage and rises in the same polarity for the first half cycle. That is what makes the fast rise. All are going up or down together. Each harmonic is therefore said to be "phase-locked" to all the others. This condition repeats continuously. Now.. Suppose we consider only the fundamental frequency, the 3rd and 5th harmonic of the fundamental at 1 Khz. Phase distortion shifts the phase of each of these harmonics by a different fixed amount for each harmonic. This distorts the waveform. The question becomes, can you hear this distortion? Suppose we generate this spectrum using THREE SEPARATE INDEPENDENT SINE WAVE GENERATORS, one at 1 KHz, one set at 3 Khz and the last set at 5 Khz. We will mix them together in the correct proportions to make a crude square wave. That could be 1V, .33V and .2V respectively. There will be no way to phase- lock each of these generators to one another making the phase relationships totally random and continuously changing because of the slight frequency errors between them. Each generator will be adjusted a closely to the proper frequency as possible using a frequency counter to begin the experiment. Connect the mixed signals to an oscilloscope and to an amp driving a set of headphones. You will see the waveform on the oscilloscope slowly crawl and squirm through every possible waveform that these three sine waves can produce. You can refine the frequency of each generator by adjusting each to get the most stable waveform you can get. For an instant, every once in a while, you will be able to get it to resemble a crude square wave. While watching the scope for visual clues, listen to the sound in the headphones to see of anything in the sound corresponds to the change in the waveform on the scope. I submit that you will not be able to hear any change at all! I couldn't! Only when one of the generators was off-tuned enough to create a beat note (a wa-wa-wa sound) could I hear any change. Note that the phase distortion generated by a loudspeaker can not cause the phase of harmonics to rotate as in this experiment, but only to be shifted by some fixed amount from where it should be. That is, the waveform will be wrong, but totally stable. I'll admit that not to many people (other than equipment manufacturers, that is) will have three sine wave generators laying around as I did, but some of you may have two. You might also be able to do it with only one by recording the fundamental frequency on a cassette deck then playing it back into the mixer while using the same generator to make the 3 rd harmonic. The 5th harmonic is really not needed to prove the point. I encourage everybody who has the equipment to try this experiment! I would like very much to hear if others can hear a change as the phase changes. Al K. Quote Link to comment Share on other sites More sharing options...
John Warren Posted June 7, 2004 Share Posted June 7, 2004 ---------------- On 6/7/2004 8:16:01 PM Al Klappenberger wrote: John, Your objections are noted. That makes ONE OF US! >>you or me, I'm a bit confused? which one is the "one" and which one is the "us"? .................... Oh, BTW: Here's a little quote from somebodies web site:. ***Please note that manufacturing rights are the property of The Audio Engineering League. Sounds like an equipment manufacturer to me. >> I said "please" and what of it? I like that statement. It makes perfectly reasonable sense given that the contents of a few of the pages contain intellectual property (the 2404H and the dual 2123J Projects). Al K. >>Now it's your turn... Here let me start it for you... Blah, Blah, Blah... ---------------- Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted June 7, 2004 Share Posted June 7, 2004 Guys, Here's more evidence that phase errors don't matter. The attached graphic is a plot of the "transfer function" of one of my modified Belle Klipsch speakers with the mike at two different distances represented by the two traces (black and yellow). The top plot is the phase response. Each "tooth" of the sawblade represents a 360 degree change in phase at each frequency. As you can see, phase changes so fast your ear / brain combination can't possibly follow it. In addition it is drastically different at every place in the room! Your brain has long since given up trying to sort out something that is so random. Another big scare factor people always talk about is "group delay". This is defined as the "slope" of phase change with frequency change. On the plot, it is the angle of each tooth with respect to the next. In an extreme case it would show as a curve rather than a straight line on each "tooth". A crossover network contributes its biggest group delay distortion right at the crossover. That's at 7500 Hz in this speaker (the red marker). Can you see a change in the slope of the "teeth" there compared to others? I can't. This is an extreme-slope network too! It admitadly has the worst group dealy distortion of any type network. Al K. P.S. I just looked more carefully at the phase plot below the woofer / squawker crossover at 700 Hz. You can clearly see the spacing between the "teeth" is tighter down below 700 Hz. I believe this is due to the longer path length from the woofer. This makes more time dealy. Quote Link to comment Share on other sites More sharing options...
Shock-Late Posted June 19, 2004 Share Posted June 19, 2004 Nice informative post. Arkytype, did you remember if the k55v/511B/beyma CP25 sounded "too soft" when still using the AA network? I'm using EV SM120 mid horns, would like to upgrade the tweeters... i find the T35 rather harsh and a bit too loud on some music now that i modded my AA x-over (1uF bypass x-over) But that said, I like some "bite" in the treble and don't want my scalas to sound overly soft. knowing that I wont upgrade my x-overs before a long time, should I still buy some CP25? What's your advice? Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted June 20, 2004 Share Posted June 20, 2004 Shock, Before you buy a new set of tweeters, try putting an adjustable "L" pads in the tweeter cables first. I bet that will solve the problem and save you a bundle. Al K. Quote Link to comment Share on other sites More sharing options...
sunnysal Posted June 29, 2004 Share Posted June 29, 2004 al where I can I see more info on the extreme slope x-overs. have you designed them for k-horns yet? regards, tony Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted June 29, 2004 Share Posted June 29, 2004 Anthony, There's some details on my web site about the new networks (alkeng.com). I have not release the design to the DIY group yet for the Khorn version becasue I am still tweaking some details. The 600 Hz version for the LaScala running 2-way is there for download though. I may not be able to release the 5800 Hz design at all becasue the layout is so critical. Time will tell though. Al K. Quote Link to comment Share on other sites More sharing options...
Colin Posted June 29, 2004 Share Posted June 29, 2004 Nobody within the fall-out radius of Arkytypes seminal home music reproduction system has an excuse NOT to email him and get his fat butt over to hear his system. It is NOT the end all and be all of dream systems, but the ALK ES crossovers, with Behringer EQ, larger JBL 511 lens and Beyma baby-cheek tweeters is a smooth combination with his vintage solid-state McIntosh receiver. It is as thoughtful and economical improvement to big ole horns as any I have heard. Caveat emptor: I am only saying nice things so ALK will give be a discount on his ES crossovers. (just kidding as usual; still debating bi and tri-amping, to get more bass power cheap) Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted June 29, 2004 Share Posted June 29, 2004 Colin, CAREFULL! Somebody might say that you are on my payroll! Al K. Quote Link to comment Share on other sites More sharing options...
Colin Posted June 29, 2004 Share Posted June 29, 2004 Well, in the interest of full disclosure: I am blonde, blue-eyed, extra padding from living so large Quote Link to comment Share on other sites More sharing options...
J.4knee Posted June 29, 2004 Share Posted June 29, 2004 OK informal poll here: How many of us needed a lift gate to pick our jaw off the floor when we saw Q-Man's "crude" drawing? I thought I could pee in the tall grass with the big dogs because my rig will have 3 La Scala's across the front 2 Heresy II front effects and 3 Heresy II surround and rear center speakers. Q-Man you have more La Scalas used for front effects and surrounds than I have my main array. Did you do the JBL/Altec/John W mod to all of your K-horns or just the front 3? I know your mains and center have it I saw that in your K-horn center thread. Not to mention but all 10 channels you have are all Mac powered correct? WWWWOW! Quote Link to comment Share on other sites More sharing options...
Colin Posted June 29, 2004 Share Posted June 29, 2004 pee in the tall grass with the big dogs gee, can I steal that? Q-mans drawing? How about ALKs explanation! Whoof! Quote Link to comment Share on other sites More sharing options...
J.4knee Posted June 30, 2004 Share Posted June 30, 2004 Sure you can steal it. But if I had my prefernce you'd rent it. Yeah Al's explantions are always impressive kind of like taking a filter design class with no homework required. I should not be so overly wowed by Q-Mans stuff by now as I followed his K-Horn center thread fairly closely but his stuff still just amazes me. The man is a true craftsman. Quote Link to comment Share on other sites More sharing options...
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